Cartridge-powered piston type tool



F. R. HASKELL ET AL CARTRIDGE-POWERED vPISTON TYPE TOOL March 13, 1962 5Sheets-Sheet 1 Original Filed May l0, 1955 www I lrfll March 13, 1962 P.R. HASKELL ET AL 3,024,666

CARTRIDGE-POWERED PISTON TYPE TOOL Original Filed May lO, 1955 5Sheets-Sheet 2 IN VEN TORS Pf//L/P E? Has/(ELL. P/cH/IPD E EVA/v5. ByPAUL ETCHPEL JR YL E E CON/v0.9.

March 13, 1962 P. R. HASKELL ET AL 3,024,666

CARTRIDGE-POWERED PISTON TYPE TOOL Original Filed May lO, 1955 5Sheets-Sheet 5 IN VEN TOR5. PH/L l .a P. Has/(ELL. Plc/4A po E'. EvqNo'.

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Mv/MW March 13, 1962 P. R, HAsKs-:LL ET AL CARTRIDGE-POWERED PISTON TYPETOOL Original Filed May l0, 1955 5 Sheets-Sheet 4 y V EN TOR5. PHIL P l?Ash/EL L. Plc-HAP@ EEvA/vs By PAL/z. /Z /L-rcHPEL :Je

LYLEB. CoA/Noe TOP/VEI March 3, 1962 P. R. HASKELL ETALCARTRIDGE-POWERED PISTON TYPE T001.

Original Filed May l0, 1955 5 Sheets-Sheet 5 @m @n h Q stv m N5 E mWSEH@ 0 NH .ww n IHEM A 5K.: WAH@ www H/Y PPPL United States Patent@ffice 3,024,666 Patented Mar. 13, 1962 3,024,666 CARTRIDGE-PWEREDPISTON TYPE TOOL Philip R. Haskell, Fairfield, and Richard E. Evans,Sonthport, Conn., Paul A.. Ketchpel, Jr., West Englewood, NJ., and LyleB. Connor, Enno, Fla., assignors to Remington Arms Company, Inc.,Bridgeport, Conn., a corporation of Delaware riginal application May 10,1955, Ser. No. 507,281. Divided and this application Sept. 9, 1960, Ser.No.

19 claims. (ci. sto- 358) This invention pertains to improvements inexplosively actuated or cartridge powered tools, and provides a tool ofthis type of unique construction which is characterized by extremecompactness, lightness in weight and ease of manipulation with a minimumof effort, and which furthermore is substantially foolproof.

This application is a division of our copending application SerialNumber 507,281, tiled May l0, 1955.

In its various modications the tool of the invention is adapted forperforming a wide variety of work functions, such as the punching ofholes, riveting, the swaging of terminals or sleeves on electricalcables for terminating or uniting the same, the uniting of electricalconduit sections by means of an interposed coupling member, as well asthe securing of threaded members on electrical conduit terminations,etc.

The tool of the invention comprises in its essentials and in accordancewith a preferred modification, an elongated frame member of steelcomprising a tubular or barrel section terminating at one end in ahook-like retainer arm of substantially C-shaped configuration formounting a work piece to be operated upon. The C- shaped retainer arm ofthe frame mounts appropriate bushings or dies and clamping means forreception of a work piece. Within the barrel section is slidablydisplaceable a piston which mounts on its forward end a work tool, suchas a hole puncher, cable swager, riveting plunger, etc. The tubularsection of the frame is of reduced aperture at its muzzle end to providea shouldered impact face for arresting forward motion of the pistonthereat. The muzzle end is, in addition, appropriately apertured forpassage of the work tool therethrough to work engaging position with awork piece held in the retainer arm. A shock absorbing assembly ismounted on the piston for preventing injury to the equipment on impactof the piston with the impact face of the frame, particularly if thetool is fired inadvertently with no workpiece mounted in the retainerarm.

The breech end of the barrel section is closed by means of a barrel pluginsertable therein, this plug having a hanged head which overlies theend of the frarne thus to prevent incorrect or wrong-endto assembly. Thebreech end of the frame as well as the barrel plug are transverselyapertured and counterbored for insertion of a relatively massivecartridge chamber plug having an enlarged head which seats in thecounterbore, thus again preventing incorrect assembly. This chamber plugcontains a bore extending axially through the head for insertion of acartridge, whereby the tool is cartridge chambered substantially atright angles to the barrel axis, a feature which permits ofsubstantially shortening the effective length of the tool and eliminatesthe necessity for safety precautions such as otherwise are required inconventional constructions wherein the cartridge chamber is aligned withthe barrel. The cartridge chamber has access to the barrel through asidewall outlet and an aligned bore extending through the end of thebarrel plug.

In the tiring position the piston is disposed at the breech end of theframe barrel and against the barrel plug in a relatively short barrelsleeve which rests against a shoulder of the frame barrel and is held inpositionl by the barrel plug.

Mounted adjacent the cartridge chamber opening is anelongated ejector,one end of which engages a slot in the upper face of the cartridgechamber plug forassuring proper alignment of the outlet passage thereofwith the aligned barrel plug outlet passage aforesaid. This ejectorispivotally mounted on the frame and pivots between cartridge seating andejecting positions.

The tubular section of the frame is longitudinally slotted along itsupper outer sidewalls for slidable reception of a cover havingdownwardly extending and turned in sidewalls for lockingly engagingthese grooves against the explosive action of the tool when fired. Thiscover, when appropriately assembled on the frame as noted below, islongitudinally displaceable between loading and tiring stations. Itmounts on its breech end a firing unit including a tiring pin which, inthe firing position of the cover, is disposed in alignment with the rimof a cartridge inserted in the cartridge chamber for ring the same. Thetiring unit also includes a firing hammer or bolt which is displaceablelongitudinally of the cover. Mounted on the cover adjacent this hammeris a safety locking device, which takes the form of a cross slidemember, and which prevents tiring of the tiring unit except when thecover is adjusted to the firing station and the cross slide adjustedthereat to a firing position.

The underside of the frame mounts an appropriate handle for gripping thetool in one hand while the other hand is employed to manipulate a crossslide safety device and also actuate the trigger of the tiring unit.

One of the most important features of the tool is a novel shockabsorbing assembly mounted on the piston for preventing injury to theequipment on impact of the piston with the impact face of the frame,particularly if the tool is tired inadvertently with no workpiecemounted in the retainer arm. This shock absorbing mechanism comprises anelastically deformable member which is adapted to absorb the excesskinetic energy for stopping the piston at the impact face after the worktool has performed its function. The other is a plastically deformablemember for absorbing such excess kinetic energy as cannot be taken up bythe elastically deformable unit, and which comes into play particularlyif the tool is fired with no workpiece mounted in the retainer arm.These two units are mounted in axial alignment on the piston so that theelastically deformable shock absorber absorbs the initial impact to itsmaximum extent whereupon the residue is absorbed by the plasticallydeformable component. The elastically deformable unit is of laminatedconstruction and in its preferred embodiment, comprises an axiallyaligned assemblage of metal rings, preferably of steel, interleaved withwhich are other rings formed of fibrous material impregnated with anelastic polymer, preferably woven nylon fabric impregnated withneoprene.

The rear end of the piston terminates in a protuberance of relativelysmall bore as compared to the piston proper or barrel which protuberanceseats, in the tiring position, in a bore of substantially correspondingdiameter formed in the inner end of the barrel plug and which has accessto the cartridge chamber through the outlet apertures of smaller boreabove mentioned. This relatively small bore in which the protuberantpiston terminus seats, is of such diameter and length as to assurecomplete burning of the powder charge before this piston protuberancepasses out of the conforming barrel plug bore, and thus assures that thepowder charge will not snuff out.

Having thus described the invention in general terms, reference will nowbe had for a more detailed description of the construction andadditional novel features of the invention, to the accompanying drawingswherein:

FIGURE l is a longitudinal sectional elevation through the entire toolassembly showing the tool in condition for ring. FIGURE la is anenlarged fragmentary sectional view of the piston assembly showing indetail the shock absorbing features of the construction; FIGURE 1b is agraph idealizing the loadcompression characteristics of the shockabsorbing construction shown in FIGURE 1a.

FIGURES 2 and 3 are views similar to FIGURE 1, but subsequent to tiringand showing the advance of the piston and hole puncher `assembly insuccessive stages to the hole punching position.

FIGURE 4 is a partial showing, similar to FIGURE 1, but illustrating thetool in the cartridge ejecting or loading condition,

FIGURE 5 is a fragmentary sectional plan view as taken at 5--5 of FIGURE3.

FIGURE 6 is a sectional plan view of the ring unit in the tiringposition as taken at 6 6 of FIGURE 1.

FIGURES 7 and 8 are enlarged, fragmentary sectional details of theFIGURE 6 showing.

FIGURE 9 is an enlarged sectional detail similar to a. portion of FIGURE6, but showing the positioning of the tiring mechanism just prior torelease of the firing bolt or hammer.

FIGURE 10 is a view similar to FIGURE 6 but showing the positioning ofthe mechanism immediately following the ring.

FIGURE 11 is an enlarged longitudinal sectional detail showing actuationof the tiring pin by the hammer at the instant of firing.

FIGURE 12 is a View in side elevation and partly in section of a furthermodification of the invention ernployed for swaging a terminal lug on tothe end of an electrical cable; while FIGURE 13 is a sectional plan viewof the completed operation.

FIGURE 14 is a plan view illustrating the application of the FIGURE 12modification to the joining of two cable ends by a coupling sleeve byemployment of a double swaging operation.

Referring to FIGURES 1-11, inclusive, of the drawings, the hole punchingmodication of the invention shown comprises a frame, identifiedgenerally by numeral 1, consisting of a tubular barrel portion 2extending from the breech end 2a `at the left to the muzzle end 2b atthe right, and a generally C-shaped frame extension comprising a Worksupport 3 in general longitudinal alignment with the barrel portion 2and connected therewith by a curved shank 3a. The breech end of thebarrel portion 2 is of slightly enlarged bore as compared to the muzzleend thereof and thus provides a shoulder 4 against which a relativelyshort sleeve barrel 5 is held by means of a barrel plug 6 inserted inthe breech end of the barrel. The barrel plug is locked in the positionshown by a cylindrical cartridge chamber plug 7, which extendstransversely of the barrel axis through suitable holes 8, 9 drilled inthe barrel plug and the breech end of the barrel portion 2,respectively.

The cartridge chamber plug 7 is provided with an enlarged head 10 whichseats in the counterbore 11 of the barrel plug, thus to maintain theassembly locked in position as shown in FIGURE 1.

The mouth of the chamber plug is radially slotted to receive an ejector(to be described), and to locate chamber plug 7 in proper longitudinaland radial position in the bores 8, 9, the cylindrical wall of the plugis notched for reception of a pin 12, backed by a small compressionspring 13, mounted in an axial bore 13a of the barrel plug 6.

In the firing position shown in FIGURE 1, a piston 14 is slidablydisposed in the sleeve barrel 5, and to which is secured a workimpression or punching tool, such as hole punching tool 15, positionedin advance ofthe piston in the smaller inside diameter region of thebarrel portion. Thus, the piston 14 together with work tool 1S comprisesa driven assemblyl The work tool 15, shown as a hole puncher, is securedto or formed integral with a shank 18, which extends through la centralsleeve member 1811 of the piston 14 and is secured to the piston bymeans of a piston cap 19 threaded on to the breech end of the shank 18.

For purposes above noted, to be explained in detail below, and as shownin FIGURE 1, the breech end of the piston cap 19 terminates in aprotuberant extension 20 of considerably smaller diameter than thepiston 14, which extension in the action or tiring position, rests in aconforming bore 20a drilled in the inner end of the barrel plug 6.

The cartridge plug 7 has formed in the upper portion thereof a bore 21for insertion of a blank cartridge 22 the cavity below the cartridgeforming an explosion chamber which has access through aligned openingsin the sidewall of the chamber plug and the forward end of the barrelplug, as at 23a, 23 to the bore 20a of the barrel plug.

Thus when the cartridge is tired, the piston and puncher assembly isimpelled progressively forward by the generated power gas as illustratedin FIGURES 2 and 3 until the end of the puncher has advanced to theposition shown in FIGURE 2 to punch a hole in. or swage a workpiece 58,as discussed later herein. The piston and puncher assembly is thereuponbrought to rest by engagement of the forward end of the piston 14 with ashouldered impact face 24, FIGURES 1-5, of conforming configurationformed at the muzzle end of the tubular barrel section 2, at which thebore is tapered `to an outlet passage 25 of relatively small borethrough which the explosion gases escape as explained below.

The tubular frame section 2 is longitudinally slotted through its uppersurface this slot being offset somewhat from the axis of the frame.

Mounted in this slot and partially closing the same is an insert member38, as shown, which is positioned against one side of the slot. Thisinsert member is secured to the frame by means of screws, as at 39,which extend through holes in the sidewall of barrel portion 2 and intothreaded engagement with the insert member 38, thereby clamping theinsert member to the frame. For additional strength the screws 39 aresupplemented by dowel pins 41, which also extend as shown, through thesidewall of the barrel section 2 and into suitable apertures provided inthe insert member 38, these dowels frictionally engaging the frame andinsert member in a tight tit. The slot is wider than the member 38 forpurposes to be described.

The frame 1 is provided with a cover or carriage 50 having in end view arelatively flat C-shaped configuration, with turned in lower lateraledges. The barrel section 2 is correspondingly grooved along the upperedges of its opposite outer sidewalls whereby the cover may be slidendwise onto the frame in vertically locking engagement therewith.

Mounted on the breech end of the cover is the firing unit 5S, FIGURES1-4 and 6-12. Mounted adjacent thereto is a cross slide protectivedevice 56 which is transversely `adjustable to locking, ejecting andtiring positions, and which prevents tiring except when adjusted to theposition last mentioned, as more fully described, for example, inapplication Serial Number 507,281, led May 10, 1955, of which thisapplication is a division.

Mounted on the muzzle end of the frame is a clamping device 57 whichclamps the work piece 58, in which a hole is to be punched in the Cterminus or work support 3 of the frame, The work clamping device mayhave modied forms according to the configuration of the workpiece, orthe operation thereon to be performed, as will become apparent.

For returning the piston 14 from the impact face 24 of the barrelportion 2, against which the piston rests after firing as aboveexplained, a piston return bolt 63 is tapped vertically through thecover as shown in FIG- URES 2, 4 and l2, with the lower end of this boltprojecting into the width of the aforementioned longitudinal slot of thebarrel alongside the member 38 and for a sufficient depth as shown inthe several figures of the drawings to engage the piston as the cover 50is displaced to the left from its ring position of FIGURES 1-3, to itscartridge ejecting position of FIGURE 4. It will be noted, referring toFIGURES l, 2 and l2, that the slot extends at the muzzle end of thebarrel portion 2 beyond the piston impact face 24, and is thus protectedfrom impact by the piston even if the shoulder 24 is set back byrepeated impact.

Referring more particularly to FIGURES l-4, a shallow axially extendingslot 65, is provided in the upper face of the barrel section 2 near thebreech end, in which is mounted an elongated cartridge ejector 66, whichpivots on a pin 67 retained in a transverse bore of the frame. Theejector 66 is actuated by displacement of the cover Si) as follows: Asthe cover is retracted from the tiring position of FIGURE l to thecartridge ejecting position of FIGURE 4, a transversely extending pin 61mounted on the under side of the cover engages a concave cam face 69 ofthe ejector and rotates it clockwise to the canted position shown inFIGURE 4 to eject the cartridge shell 22 through an opening 70 formed inthe cross slide 56. The under face of the frame cover 50 is providedwith a sloping ramp, as at 71, to permit of this actuation of theejector. With the cover in the position of FIG- URE 4, a new cartridgemay be inserted through the cross slide opening 70. until the rimthereof engages the cartridge ejector end 72 of the ejector, whereuponthe frame cover Si) is returned to the position of FIGURE l. As thecover is thus moved into position a second sloping ramp 73 provided onthe opposite under side of the cover engages the rim of the cartridgeand seats it in the cartridge chamber cavity 21 with the shell rim iushwith the upper edge of the cavity as shown in FIGURE l, while at thesame time returning the ejector 66 to the cartridge seating position ofFIGURE 1 as the frame cover pin 61 rides off the cam face 69. In orderto provide for seating of both the cartridge shell 22 and the ejector 66flush with the upper surface of the chamber plug 7, this surface isperipherally recessed, as at 7 0a and radially slotted, as at 7Gb,FIGURE 4, appropriately to seat the shell rim and ejector, respectively.

Referring to FIGURES l and 6-1l, inclusive, the firing unit S5 comprisesa housing 74 secured to the frame cover 5l) by means of screws 75. Thehousing is drilled for axially displaceable reception of a firing boltor hammer 76 having an intermediate portion 76b of enlarged diameterwhich is slidably displaceable in the frame bore 76a. From one end ofintermediate portion 76h there extends a `hammer terminus 77 of smallerdiameter which is sleeved through a hammer spring 78 housed in anopenended sleeve-like retainer 79, the inner end of which is threaded tothe housing as at 79h. From the opposite end of the enlarged hammerportion 76b there extends a second hammer terminus 80 having a iiatunder face 81, FIGURE ll, which terminates adjacent the enlarged hammerportion 76]; in a stepped cam face 82 for actuating a firing pin 83 inthe manner illustrated in FIG- URE ll.

As shown in FIGURE l, the at under face 81 of the terminus 80 normallybears against the enlarged head of the firing pin 83, which latter ispositioned in a bore extending through the housing 74 and into the framecover 50.

The housing 74 also mounts in a laterally extending slot 86 thereof,FGURE 6, a trigger 87, which projects horizontally from the housing,FIGURES 6-10, inclusive, the trigger being pivotally mounted on a pin 88extending through the housing 74 and spanning the slot 86. The

trigger is normally maintained in the position of FIGURE 7 by acompression spring 89, FIGURE 6, disposed in a bore of the housing.Slidably mounted in a bore of the trigger is a sear 91 having anarrowed, linger-like upper end which normally engages a notch 92 in theside of hammer terminus with a slight clearance as shown in FIGURE 7.

Referring to FIGURES 6-10, inclusive, as the trigger is gripped androtated clockwise about its pivot point 88, against the restoring actionof the compression spring 89, the upper end of the scar 91 engages thehammer shoulder 93, formed by enlarged intermediate portion 76b, andforces the hammer to the right against the compressive restoring actionof the spring 7S, until the position assumed is about that shown inFIGURE 9, at which point the hammer shoulder 93 overrides the roundedupper end of the scar 91 and thus depresses the scar against therestoring action of the sear spring 94, thereby permitting the bolt tobe snapped smartly to the left by the restoring action of the hammerspring 78, in the manner shown in FIGURE 10i. As the hammer is thussnapped to the left, the flat under face 81 of the hammer terminus 80rides along the head of the firing pin 33 until the ring pin is engagedby the camming surface 82 formed on terminus 80 which abruptly depressesthe -ring pin to fire the cartridge in the manner shown in FIGURE 1l.Overcarry of the hammer 76 compresses a hammer return spring 84, asshown in FIGURE 10, which immediately restores the hammer to theposition of FIGURE 7, whereupon the momentarily compressed ring pinspring 85 returns the firing pin 83 to the position of FIGURE l, inengagement with the at under face S1 of the hammer terminus 8l).

In firing the tool, and to insure that the work is punched completelythrough, or properly swaged, etc., it is necessary to impart to thepiston and blade assembly an excess of say 25% of the energy actuallyrequired to punch or swage the work or to perform other operationsheretofore outlined, and, to stop the movement of the piston and toolassembly after its work is completed, a buffer is associated with thisassembly. In a preferred form of the invention, this buffer comprisestwo elements, the first being a stack of radially elastically deformablemembers and the second a ring spring type of assembly comprising one ormore members which are radially elastically deformed and under excessivestress undergo a plastic deformation. Such excessive stress may beapplied when the tool is inadvertently iired without a workpiece inplace. Under these conditions the buffer assembly must absorb anddissipate from the tool system the entire kinetic energy of the pistonand tool element assembly, there being no other resistance to theforward movement of this assembly. The construction of the tool may besuch that plastic deformation of the ring spring disables the tool, in amanner to be described, both indicating that the tool has been tiredwithout a workpiece in place and necessitating replacement of theplastically deformable ring.

As shown particularly in FIGURES l and la of the drawings, theelastically deformable shock absorbing cornponent is identifiedgenerally by numeral 16 and the elastically and plastically deformablemember by numeral 180. The function of the elastically deformable shockabsorbing component 16 is to absorb the excess kinetic energy of thepiston, over and above that required to punch a hole in, or swage theworkpiece 58 when the tool is fired and the piston impelled thereafteragainst the impact surface 24 of the frame. The function of theplastically deformable member is to absorb and dissipate from the toolsystem the excess kinetic energy of the piston on tiring, which is nottaken up in punching or swaging the workpiece, and in elasticdeformation of the shock absorbing member 16, or which is not take-nv upby the shock absorbing member 16 alone `such as would be necessary, forexample, if the tool is inadvertently fired with no workpiece in theretainer arm.

In order for the elastically deformable shock absorbing component 1 6satisfactorily to perform its function above stated, it must be designedto meet two rigid requirements. First, the compression modulus ofelasticity of this member must be such as to decelerate the pistonwithout exceeding the tensile strength of the projecting tool element.In this connection it will be observed that upon impact of the pistonagainst the frame impact face 24, tending abruptly to stop the piston,the inertia of the tool element places the same under tension so that ifthe piston is stopped too abruptly, the tool element will fail intension. Therefore the shock absorbing component 16 must have a modulusof elasticity which is sufficiently low as to decelerate the piston at arate sufficiently low that the tensile strength of the plunger toolelement is not exceeded. The second requirement which the shockabsorbing component 16 must meet is that it must be capable ofsupporting a compression load equal to the tensile strength of the toolelement. This is explainable as follows: As the front face of the pistonimpacts the frame impact face 24, the shock absorbing component becomesanalogous to a compression spring, the rear end of which is connectedto, and compressed by, the piston cap 19 threaded onto the terminus ofthe tool shank 18. The momentum of the tool element is thus resisted bythe force exerted by the spring as it is compressed. If this spring hastoo high a compression modulus, the tool element will fail in tension.Metal springs, even in coiled forms of low modulus, have neverthelesstoo high a compression modulus, and, being made of metal, a shock waveis built up that outraces the load velocity and sets the spring. On theother hand, solid plastics have too high a compression modulus, and, inaddition, cannot withstand the compressive forces which their highmodulus quickly produces. For example, leather approximates asatisfactory modulus, but fails in compression loading during repeatedcycles, because its outer tough fibers break loose from their supportingmatrix. Rubber and rubber-like material, including the synthetic rubberssuch as neoprene, display a compression modulus somewhat under that ofleather, so that considerably more stroke is required to store the sameenergy. While rubber and equivalent materials can withstand heavyloading with elastic recovery, they require support within a containerboth to raise their natural modulus and to prevent shredding failureunder load. As thus compressed in a container, for example, in a steelsleeve, rubber behaves like. an incompressible fluid, exertingtremendous hydraulic pressure on the surrounding container. The strengthof the retainer thus required cannot be provided in a tool of reasonablesize.

In accordance with one aspect of the present invention, this problem issuccessfully solved in a compact structure by making the elasticallydeformable component 16 of a laminated construction and consisting of aseries of axially aligned metal rings 181, such as steel shims, whichare interleaved with other rings 182 formed of woven fabric, preferablywoven nylon fibers, which are impregnated with an elastic polymer,preferably neoprene. This laminated arrangement is assembled, in axialalignment as shown on the steel assembly tube 181) between an impactplate 184 mounted on the forward end of the assembly tube and an annularspacer member or backing plate 185 assembled on the rear end of theassembly tube. To facilitate this assembly, the assembly tube is formedwith a flanged terminus 186 at its rear or left end in the drawing andthe backing plate 185 is formed with a conforming axial counterbore,which seats against this shoulder. The assembly tube at its opposite endis crimped up against the impact plate 184 as at 187, thus to lock theentire assembly together.

In this assembly. in the elastic polymer-impregnated fabric rings 182,such as the neoprene impregnated woven nylon fibers, the fibers act asstay bolts to hold the elastic polymer or neoprene from expanding, andthus absorb the lateral strain on these rings resulting from impact ofthe piston against the frame impact face 24. Neoprene has been found tobe a convenient elastic binder for nylon fibers, and thus facilitatesthe establishment of a synthetic modulus of elasticity which neither thenylon alone nor the neoprene alone can possess. The surface of the steelshims separating the layers of impregnated fabric are preferablyroughened, as by sand-blasting. These shims frictionally support thefabric layers, giving added strength and retarding radial expansion;their friction against the fabric also dissipates a substantial amountof energy. When, as illustrated, the plastically deformable member 180is used in conjunction with the elastically deformable component 16, thelatter is of such length and construction as to sustain without plasticflow a compression substantially equal to that which will initiateelastic deformation of the member 180.

Referring to FIG. lb, by appropriately dimensioning or apportioning thenumber of elastic polymer impregnated fabric rings 182 in relation tothe metal rings 181, the modulus of elasticity 138 of the elasticallydeformable component 16, may be sloped as desired within limits, thus toadjust the deceleration of the piston in accordance with therequirements above stated.

Because of the requirement that the piston weight be minimized, theamount of elastic shock absorption that can be built into the shockabsorbing component 16, is limited, and the excess must be taken up bythe plastically deformable member 130, both as regards excess kineticenergy resulting from the hole punching or cable swaging operation, andmore particularly as regards the excess kinetic energy resulting frominadvertent tiring of the tool with no workpiece mounted in theretaining arm. This latter is strictly a protective feature to preventinjury to the piston and the tool itself resulting from such inadvertentfiring. To this end the plastically deformable member 180 comprises aring made of a malleable metal like aluminum or an aluminum alloy ofsuch dimensions that it will fail in compression before the other toolcomponents will fail in tension. That is to say, the compressionstrength of the plastically deformable member 180 must be substantiallyless than the tensile strength of the tool frame, punching or swagingelement and piston. It will be noted in this connection that when thepiston impacts the frame impact face 24, the tubular portion of theframe is placed under tension. Likewise, the punching or swaging elementis placed under tension due to its inertia. As shown in FIGURE l, theplastically deformable member 180 of malleable metal is of trapeziumconfiguration, as viewed in axial section, and is mounted between thebacking plate and the piston cap i9, both of which are made of a metalhaving a high elastic limit, such as steel. The abutting surfaces 190,191, between the plastically deformable member and the adjacent steelbacking plate and piston cap members 185, 19, are preferably sloped inaccordance with the minimum slope or friction angle of the contiguousmetals, i.e., aluminum vs. steel in the preferred modification as abovementioned, thus to enhance the energy absorption by the malleable metalplastically deformable member 18;? as the latter is plastically deformedby compression. Thus the camming angles of the sloped surfaces 190,1511, approximate the friction angles between the contacting metalsurfaces, so that the yield strength of the plastically deformablemember 180, is mechanically increased by the friction. The plasticallydeformable member `180 shown, approximates a rectangular stress-straindiagram for maximum efficiency of energy dissipation as a function ofpiston stroke. The maximum force developed thereon accordingly neverexceeds a value exceeding the tensile strength of the tool element andshank.

Referring again to FIG. lb, the plastic deformation of the member 180may be designed to occur at any given load level such as 192. As aresult, therefore, of the composite assembly comprising the elasticallydeformable shock absorbing component 16 and the plastically deformableenergy absorption member 180, the composite load compression graphthereof will be approximately as indicated at 158, 192 of FIG. lb. Thatis to say, as the piston impacts the frame shoulder, the impact of thepiston against the shoulder will at `first be gradually absorbed byelastic deformation of the shock absorbing member 16 (and, of course,any elastic deformation of the ring spring, or plastieally deformablemember 150 as does occur), along the line 188 of FIG. 1b, until a loadcorresponding to the level 192 is reached at which the elastic limit ofmember 180 will be exceeded whereupon additional load will be assumed byplastic deformation of the plastically deformable member 180 which holdsthe load substantially constant thereafter at the level 192 as shown inFIG. lb.

It should be noted that in the ordinary usage of the tool theplastically deformable member 180 is not deformed beyond its elasticlimit and that -it is only in the event that the tool is operatedwithout a workpiece iu place that the stress applied to this ring issuicient to plastically and permanently deform it. Under some conlditions, it is desirable that such permanent deformation of theplastically deformable member 180 be indicated and disable the tooluntil such is replaced. This can be accomplished by providing thatpermanent deformation of the plastically deformable member 180 increasesits diameter beyond the bore diameter of the barrel sleeve 5. In thiscondition, when an attempt is made to retract the piston to firingposition, a margin of the plastically deformable member 180 will engagethe end of the barrel sleeve 5, preventing complete retraction of thepiston.

It should be stated, however, that while the buffer above described maycomprise both an elastically deformable component 16 and -a plasticallydeformable member 181), where space requirements permit, it is possibleto so extend and enlarge the elastically deformable member 16, as toprovide the energy absorption capacity needed for firing in the absenceof a workpiece without the use of plastically deformable member 180.

While the elastically deformable component 16 is a buffer and preferablycomprises layers of impregnated fabric alternating with metal shims,under some conditions it is possible to omit the shims and placesuccessive layers of impregnated fabric in face-to-face relation. It isessential, however, that the buffer comprise a plurality of rings ordisks of fibrous material held in an elastic impregnating medium, suchthat the transversely disposed elastic bers and the elastic impregnantinteract to oppose radial deformation while enabling the requiredlongitudinal deformation.

Reverting to FIG. l, the piston impact plate 184 is likewise preferablymade of a malleable metal like aluminum or an aluminum alloy, having acompression strength substantially below that of the metal of the frame1, which latter is made of steel. The purpose of this is to assure thatthe impact plate will fail through cornpression before the steel frameis broken under tension, this being an additional safety precaution inthe piston construction. Moreover, the stress incident to stopping thepiston assembly, either in normal usage or in firing without aworkpiece, is received by the main frame barrel 2, and not by the worksupport 3, thus avoiding any bending stress in the curving connectingshank 3a.

Referring to FIGURES l-3 and 5, the workpiece 58 in which a hole is tobe punched is positioned in the hook-like retainer arm 3 of the toolframe against an annular shearing die 320 mounted in a bore 321 of theframe retainer or work support 3. The die 320 is resiliently held inplace by means of a detent 322 which engages a peripheral groove '323 inthe exterior surface of the die, this detent being backed by a smallcompression spring 324, for resilient displacement whereby the die 320may be snapped into place or removed. Mounted on the piston 101 in themanner above described and integral with shank 18 is a plunger 325 of adiameter slightly less than that of the die aperture 326. The clearancebetween the punch and die is preferably somewhat greater than thatcommonly used in die sets operated by conventional means. The workpiece58 to be punched such, for example, as the angle iron shown, is mountedon a supporting screw 325 which threads through the base of the frameretainer arm 3 as shown, this screw being adjustable up and down bymeans of the handle 329 secured to the base of the screw. Clampingdevice 57 clamps the workpiece securely against the die 320` during thepunching operation. The suitable clamping device 57 which is shownconsists of a pivotally mounted camming member 331 on the frame 1, whichpivots thereon by means 330. Camming member 331 is provided with a leverarm 332 for manipulating. When the tool is fired the piston and toolassembly 16, including the plunger 325, advances from the firingposition of FIGURE l to the punching position of FIGURE 3, thus ytopunch out a circular slug 333 from the workpiece 58 which drops downinto a cavity 334 formed in the retainer arm 3 behind the die aperture321.

It should be noted that the length of the cover 50 at its muzzle end 2bmay be extended in length to partly, or completely cover the aperture atthe top of retainer arm 3 to protect the operator from powder gases,chips, etc. when the tool is fired. This will depend largely on the sizeor shape of the work in which a hole is to be punched. In the case of anangle iron workpiece, as shown in FIGS. 1-3, extension of the cover maybe neither practical no1 necessary, the horizontally extending leg ofthe angle iron offering a measure of such protection.

As shown in FIGURES l-4, and FIGURE 6, the tool is provided with ahandle 200 of wood, hard rubber or equivalent, which is assembled on theunder side of the tubular frame section 2 by means of bolts, as at 201,202, threaded into the frame. l

In assembling the tool from its components, the piston and tool assemblyis rst inserted in the frame barrel portion 2. The sleeve barrel 5 isthereupon inserted against the shoulder 4. The barrel plug 6 is theninserted in the breech end of the frame and the cartridge charnber plug7 inserted in the aligned holes 8, 9, and rotated until the pin 12 ofthe barrel plug seats in the notch of the chamber plug. As thuspositioned, the slot 7Gb, FIGURE 4, cut in the upper face of the chamberplug 7, is positioned to seat the ejector end 72 of the cartridgeejector 66.

The enlarged head of the barrel plug 6 assures that the proper end willbe inserted in the frame barrel 2. The chamber plug cannot be inserteduntil the barrel plug has been rotatively positioned with its bore 8 inalignment with the frame bore 9. The chamber plug cannot be incorrectlyinserted by reason of its enlarged head 10 which can seat properly inthe barrel plug counterbore 11 only when the plug is inserted as shownin FIGURE l.

With the aforesaid components thus assembled as shown in FIGURE l, thecover 50 may then be slid into position on the frame, to effect whichthe piston return bolt 63 must first be removed. As the cover isadvanced to the firing postion shown in FIGURE l, the frame cover pin 61engages the shoulder 60 of the insert member 38 thus to limit theforward displacement of the cover. The cross slide protective device S6will t into place in the cover cutout 125, FIGURES l4, its cross slideportion 106 engaging the cutout. The piston return bolt 63 is thereuponinserted and threaded into the cover 50. The tool is now ready foroperation.

The method of operation is as follows: In loading the tool, the ringunit 55 is grasped with one hand and one of the fingers thereof used toshift the cross slide protective device S6 transversely to a coverreleasing position. The firing unit 55 and cover can then be drawn backto the cartridge ejecting position, thus exposing the cartridge chamber21 through the aperture 70 in the cross slide cover, into which a blankcartridge 22 is dropped. The bolt is then pushed forward, encasing thecartridge. The cross slide protective device 56 is then shifted to itsfiring position, locking the cover to the frame, whereupon the trigger87 may be pulled to fire. Thereafter the cross slide protective device56 is shifted to the cover releasing position, whereupon the cover canagain be withdrawn to the cartridge ejecting position by grasping thebreech bolt, the spent shell thus being ejected through the cross slidecover aperture or opening 70. The punched or swaged workpiece 58 can nowbe removed from the now open C of the frame retainer arm. In the case ofhole punching, the punched slug 333 will have fallen out of the toolthrough slot 334. An absolute minimum of manual motion is thus entailedfrom start to finish.

A feature of the tool resides, as above noted, in the chambering of thecartridge at right angles to the motion of the piston as illustrated inFIGURE 1. There are a number of advantages in this feature. Sincecaptive piston tools of the type shown generally have a barrel borediameter considerably in excess of the cartridge diameter, the rightangled chambering of the cartridge chamber facilitates the loading ofthe large diameter piston ahead of the relatively small shell, withoutnecessity for providing a safe, foolproof joint at the front end of thetool for muzzle loading of the piston, such as would otherwise benecessary if the cartridge chamber were axially aligned with the pistonat the breech end of the tool. Moreover, since the barrel bore isconsiderably larger than that of the shell, the total force of thepiston in the barrel plug is many times that of a conventional firearm.The cylindrical cartridge chamber member, inserted at right angles tothe piston axis, through the frame and barrel plug apertures, provides amassive locking pin which secures and resists this high total explosiveforce occurring in the barrel bore. Again a tool of the type shown,employing a captive piston which is not ejected from the tool, tends toaccumulate more powder residue than occurs in a conventional firearm.The right angle cartridge chamber assembly provides a means ofinstantaneous takedown or disassembly in the manner above described sothat all surfaces of the piston chamber and barrel bore can easily becleaned with a brush. Also the right angled cartridge chamber assemblyprovides a tool of minimum length. A much greater length of tool wouldbe required in a construction wherein the cartridge chamber is axiallyaligned with the barrel of the piston. A further advantage of thisconstruction is that a cartridge chamber plug for handling cartridges ofa given caliber can easily be replaced by other cartridge chamber plugsof similar construction adapted for the insertion of cartridges oflarger caliber, by simply making the cartridge bore of the requisitediameter and offsetting the same from the centerline whereby any caliberrimfire cartridge can be employed without necessity for relocating thefiring pin. Since the barrel plug and cartridge chamber plug assemblyprovide, upon removal, the only entry through which the piston and toolassembly can be inserted. this construction eliminates the necessity forsafety interlocks that would otherwise be required if the piston andtool assembly were side or front loaded into the tool frame.

Referring to FIGURE l, mention was made above of the fact that theterminal portion of the steel piston cap 19 is of considerably reduceddiameter as compared to the bore of the sleeve barrel S and the piston14, and that this reduced diameter terminus of the piston cap fits intoa corresponding bore 20a in the forward end of the barrel plug 6 throughwhich the explosion chamber 2l has' access to the* bore 20a through theapertures 23a,

23 in the cartridge chamber and barrel plug, respectively. Thesignificance of this is that experimental tests have shown that with abarrel of relatively large bore, such as that of the barrel 5, theinitial expansion volume for the burning powder from the cartridge 22 isprovided at so great a rate, as the piston moves forward, thatcombustion of the powder is irregular. Powder of sufficiently tinegranulation to be quick enough for a barrel of the relatively large boreof the barrel 5 is not commercially available and would be dangerous tohandle industrially even if it were. The smaller diameter protuberanceextending from the piston cap into the barrel plug bore 20a provides asmaller bore diameter during the period of powder burning as the pistoninitially moves forward, and a larger diameter bore during powder gasexpansion, the latter as the piston cap protuberance moves out of thebarrel plug cavity to permit expansion of the gases into the larger boreof the barrel 5. It will further be noted in this regard that thisprotuberance 20 on the piston cap is nevertheless of considerably largerbore than the diameter of the shell 22 itself, and thus provides aninitially exposed effective piston area large enough to apply tremendousacceleration to the piston by the powder up to the time it is completelyburned but at the same time, does not permit the powder to snuff out bythe pressure drop that might otherwise occur if the explosion chamberbore 21 had access directly to the large bore of the barrel 5. With thearrangement shown, it is not until the powder is completely burned thatthe large bore of the barrel 5 is uncovered, so that the gas, expanding,can act on the larger piston area during the remainder of travel. Alarge diameter piston has the distinct advantage of providing maximumexpansion volume for powder gas in a tool of minimum length, such asthat shown. A tool of the relative dimensions shown having a bore ofabout 1" for the `barrel 5 and an effective length of the frame barrelof about 15/3 provides an explosion chamber which should be equivalentto a barrel of about 22 in length, provided the piston were of the samecaliber as the shell.

Referring to FIGURES 2 and 3, the longitudinal slot of the frame inwhich the piston return bolt 63 is displaceable also provides a gasescape passage communieating at one end with the bore of barrel sleeve 5and at .its opposite end with the frame outlet or passage 25. Tinspassage, as shown by the dashed line of arrows in FIGURES 2 and 3, leadsthe gases above and beyond the piston and deposits them against theworkpiece clamped in the frame C arm as soon as the piston has passedout of the barrel sleeve 5. In this passage the gases expand so as tominimize the blast effect and by directing them against the workpiece,which may be substantially covered by the frame cover 50 during firing.protects the operator against them. By providing for escape of the gasesin this way they have a swept or aspirating effect on the barrelresidue. This is in contrast to expedients heretofore employed incertain captive piston type tools wherein no gas outlet passage isprovided and in which the gases are caused to expand and cool in thebarrel, with the result that such tools must be frequently cleaned.

Reference will now be had to FIGURES l2l4, inclusive, showing amodification of the invention adapted for the swaging of an electricalterminal onto the end of electrical cable or for joining two cable endstogether by means of an interposed sleeve. Assembled on the piston 14,as above described, is a swaging head or plunger 34K), having a knobbedhead 341. Mounted in the retainer arm 3, is a backing plate 342, securedin place by means of a bolt 343 extending through a bore of the retainerarm 3 and threading into the backing plate. Assuming the tool is to beemployed for swaging a terminus 344 onto the end of a cable section 345,the sleeved portion 3i6 of the termina] member is first assembled on thecable terminus 345, and the assembly then positioned against the backingplate 342, in the manner shown in FIGURE 12, and held in place in theaction or tiring position `by a modified form of work clamping device57. This form of clamping device, as shown, consists of a substantiallyinverted U-shaped clamping member 347, which spans the extended framecover` 50 and is secured thereto by means of a screw 348, this clampingmember having depending arms as at 349 adapted to engage the front faceof the workpiece assembly and hold it against the backing plate 342.

When the tool is tired the plunger 340 is advanced from the position ofFIGURE l2 to that of FIGURE 13, whereby the knobbed head 341 of theplunger swages the sleeve portion of the terminal into snug engagementwith the cable terminus 345 in the manner illustrated at 350, FIGURE 13.For joining together two cable terminals 351, 352, FIGURE 14, by meansof an interposed sleeve member 353, the swaging operation abovedescribed is performed twice. That is to say, the sleeve 353 is firstslipped onto the cable terminus 351 and the assembly mounted in the toolin the manner illustrated in FlGURE 12 and the tool tired. The secondcable terminus 352 is thereupon inserted in the opposite end of thesleeve 353 and the assembly thereupon again mounted in the retainer armin the manner shown in FIGURE 12 and the tool again fired. As a resultof these two operations the sleeve 353 is swaged to the cable terminus351 in the manner shown at 354 and to the cable terminus 352 in themanner shown at 355.

In FIGURES l2 and 13 it will be noted that the muzzle end of the cover5! is extended in length so that when the cover is advanced to thefiring position with respect to the tool frame, its forward end coversthe open C aperture of the hook-like retainer arm 3. In addition, thedepending arms 349 close the side apertures. Thus, the cover andclamping device when closed automatically and safely covers the regioninto which chips, scale, powder gas, etc. may be deposited, shieldingthe operator against the same.

Because the clamping device 57 as shown, is attached to the cover toengage the workpiece when the cover has been advanced to its tiringposition, the cover and clamping device insure that the conduit sleevewill be fully against the backing plate 342 when the tool is fired. Toprovide resilient clamping, imparting some give to the clamping devicewhen drawn into place against the workpiece, a piece of rubber 355 orthe like is interposed between the flat top portion of U-shaped member347 and the surface of cover 50, as shown. The hole through the member347 for the screw 348 should be made somewhat larger than ythe screwdiameter for the purpose.

What is claimed is:

l. An explosively actuated punching tool comprising a frame including abarrel sectionhaving a breech end and a muzzle end, a piston slidable insaid `barrel section, closure means including a cartridge chamber at thebreech end of said barrel section and having access thereto, pistonretainer means integral with the muzzle end of said barrel section, anelongated rigid member attached at one of its ends to said piston toproject therefrom towards said muzzle end of the barrel section, apunching instrumentality integral with the other end of said rigidmember, and shock absorbing means mounted for movement on said rigidmember between said piston and said punching instrumentality, said shockabsorbing means comprising a stacked assembly of laminae of interlockedfibrous material impregnated with a resilient rubber-like polymer,whereby when said shock absorbing means engages said piston retainermeans at lthe end of a piston working stroke the stacked assembly ofimpregnated fibrous material will dissipate a large part of the shock ofthe stopping of said piston, and an abutment means forward of said shockabsorbing means for engagement with said retainer means.

2. An explosively actuated punching tool according to claim l whereinthe elongated rigid member has disposed thereon a plastically`defr'irrnable member disposed between said piston and said shockabsorbing means.

3. A explosively actuated punching tool comprising a frame including abarrel section having a breech end and a muzzle end, a pistondisplaceable therein, closure means including a cartridge chamber at thebreech end of said bar-rel sect-ion and having access thereto, pistonretainer means integral with the muzzle end of said barrel section, apunching tool attached lto said piston and projecting therefrom towardssaid muzzle end of the barrel section, and shock absorbing means mountedfor movement on said punching tool and adapted to absorb energyresulting from impact of said shock absorbing means against saidretainer means at the end of a Working stroke of ysaid piston, saidshock absorbing means comprising elastically deformable and plasticallydeformable shock absorbing members disposed seriatim in the direction ofsaid impact, said elastically deformable member comprising a stackedassembly of metal laminae interleaved with laminae of fabric wovenmaterial impregnated with a resilient rubber-like polymer, and saidplastically deformable member comprising a relatively rthick section ofa malleable metal plastically deformable upon the energy absorptioncapacity of said elastically deformable member having been substantiallyreached.

4. An explosively actuated punching tool according `to claim 3 whereinsaid punching tool is a cable swaging tool.

5. An explosively actuated punching tool comprising, a frame including abarrel section having a breech end and a muzzle end terminating at themuzzle end in a hook-like arm section, a piston displaceable in saidbarrel section, breech closure means yfor said barrel section includinga cartridge chamber having access to said barrel section and accessiblefrom said breech end, and retainer means for said piston at the muzzleend of said barrel section, a cover displaceable along said framebetween a retracted position and an advanced position thereof withrespect to said frame, said cover when positioned at said retractedposition exposing said cartridge chamber and when positioned at saidadvanced position covering said cartridge chamber and the open apertureof said hooklike arm, means on said cover for clamping a workpiece insaid hook-like arm and cooperating means of said hook-like arm forclamping said workpiece in position with said cover disposed at saidadvanced position, and

' a punching tool carried by said piston adapted to fabri- `cate saidWork piece, and shock absorbing means mounted on said piston adapted todissipate energy resulting from impact of said piston against saidretainer means.

6. An explosively actuated tool according to claim 5 wherein saidpunching tool is a cable swaging Itool.

7. An explosively actuated punching tool comprising, a frame including abarrel section having a b-reech end and a muzzle end and terminating atthe muzzle end in a hook-like arm section, a piston displaceable in saidbarrel section, breech closure means for said barrel section including acartridge chamber having access to said barrel section and accessiblefrom said breech end, and retainer means for said piston at the muzzleend of said barrel section, a cover displaceable along said framebetween a retracted position and an advanced position thereof withrespect to said Aframe, said cover when positioned at said retractedposition exposing said cartridge chamber and when positioned at saidadvanced position covering said cartridge chamber and the open apertureof said hook-like arm, means on said cover for clamping a work piece insaid hook-like arm and cooperating means of said hook-like arm forclamping said work piece in position with said cover disposed at saidadvanced position, and a punching tool carried by said piston adapted tofabricate said work piece, and shock absorbing means mounted on saidpiston adapted to dissipate energy resulting from impact of said pistonagainst said retainer means, said shock absorbing means comprisingaxially aligned elastically deformable and plastically deformable shockabsorbing members, said plastically deformable shock absorbing memberplastically deformable upon the energy absorption capacity of theelastically deformable shock absorbing member having been substantiallyreached.

8. An explosively actuated punching tool comprising a frame having guidemeans for mounting a piston displaceable therealong, a piston `assemblycomprising a punching tool integral with said piston and mounted in saidguide means, means at one end of said frame for impelling said pistonassembly along said guide means and an impact member integral with theopposite end of said frame for stopping said piston assembly, andelastically deformable shock absorbing means mounted on said pistonhaving a compression modulus such as to dccelerate said piston assemblywithout exceeding the strength of said piston assembly, said means beingof laminated construction and comprising axially aligned and interleavedmetal rings and rings of fibrous material impregnated with a resilientrubber-like polymer, said means being capable of supporting acompression load substantially equal to the strength of said tool.

9. An eXplosively actuated tool according to claim 8 wherein saidpunching tool is a cable swaging tool.

10. An explosively actuated punching tool comprising a frame havingguide means for mounting a piston displaceable therealong, a pistonassembly comprising a punching tool integral with said piston andmounted in said guide means, means at one end of said frame forimpelling said piston assembly along said guide means and an impactmember integral with the opposite end of said frame for stopping saidpiston assembly, elastically deformable shock absorbing means mounted onsaid pis ton having a compression modulus such as to decelerate saidpiston assembly without exceeding the strength of said piston assemblyand tool, said means being of laminated construction and comprisingaxially aligned and interleaved metal rings and rings of fibrousmaterial impregnated with a resilient rubber-like polymer, said meansbeing capable of supporting a compression load substantially equal tothe strength of said tool, and a plastically deformable shock absorbingmember mounted on said piston assembly in axial alignment with saidshock absorbing means, said member comprising a relatively thick ring ofmaterial having a compression strength substantially below the strengthof said frame and piston assembly `and plastically deformable upon theenergy absorption capacity of said elastically deformable member havingbeen substantially reached.

1l. An explosively actuated punching tool according to claim 10 whereinsaid punching tool is a cable swaging tool.

12. An explosively actuated punching tool comprising a frame havingguide means for mounting a piston displaceable therealong, a pistonmounted in said guide means, said piston carrying a punching tool, meansat one end of said frame for impelling said piston along said guidemeans, an impact member at the opposite end of said frame for arrestingsaid piston, and shock absorbing and energy dissipating means on saidpiston comprising elastically deformable and plastically deformablemembers mounted in axial alignment, said elastically deformable memberhaving a compression modulus such as to decelerate said piston withoutexceeding the tensile strength of said piston and tool and being oflaminated construction consisting of axially aligned and interleavedsteel rings and rings of woven nylon fabric impregnated with neoprene,and said plastically deformable member comprising a relatively thickring of malleable metal having a compression strength substantiallybelow the tensile strength of said frame and piston and plasticallydeformable upon the energy absorption capacity of said elastil 3 callydeformable member having been substantially reached.

13. An explosively actuated punching tool comprising a frame including abarrel section having a breech end and a muzzle end, a piston slidablein said barrel section, closure means including a cartridge chamber atthe breech end of said barrel section and having access thereto, pistonretainer means integral with the muzzle end of said barrel section, anelongated rigid member attached at one of its ends to said piston toproject therefrom towards said muzzle end of the barrel section, apunching instrumentality integral with the other end of said rigidmember, and shock absorbing means mounted for movement on said rigidmember between said piston and said punching instrumentality, said shockabsorbing means comprising a stacked assembly of laminae of interlockedfibrous material impregnated with a resilient rubbcr-like polymer,whereby said shock absorbing means engages said piston retainer means atthe end of a piston working stroke the stacked assembly of impregnatedfibrous material will dissipate a large part of the shock of thestopping of said piston.

14. An explosively actuated tool according to claim 13 wherein saidpunching instrumentality is a cable swagng instrumentality.

15. An explosively actuated punching tool according to claim 13 whereinthe elongated rigid member has disposed thereon a plastically deformablemember disposed between saidpiston and said shock absorbing means.

16. An explosively actuated punching tool comprising a frame including abarrel section having a breech end and a muzzle end, a piston slidablein said barrel section, closure means including a cartridge chamber atthe breech end of said barrel section and having access thereto, pistonretainer means integral with the muzzle end of said barrel section, apunching tool carried by said piston, and shock absorbing means mountedfor movement between said piston and said piston retainer means and inalignment association with said piston, said shock absorbing meanscomprising a stacked assembly of laminae of interlocked fibrous materialimpregnated with a resilient rubber-like polymer, whereby said piston atthe end of a working stroke compresses said stacked assembly ofimpregnated fibrous material between said piston and said pistonretainer means, said stacked assembly of impregnated fibrous materialthereby dissipating a large part of the shock of the stopping of saidpiston.

17. An explosively actuated punching tool according to claim 16 whereinsaid punching tool is a cable swaging tool.

18. An explosively actuated punching tool comprising, a frame includinga barrel section having a breech end and a muzzle end, a pistondisplaceable therein, closure means including a cartridge chamber at thebreech end of said barrel section and having access thereto, pistonretainer means integral with the muzzle end of said barrel section, awork tool attachment element attached to said piston and projectingtherefrom towards said muzzle end of 4the barrel section, a punchingtool carried by said attachment element, and shock absorbing meansmounted for movement on said attachment element adapted to absorb energyresulting from impact of said shock absorbing means against saidretainer means at the end of a working stroke of said piston, said shockabsorbing means including an elastically deformable energy dissipatingmember comprising a stacked assembly of metal laminae interleaved withlaminae of fabric woven material impregnated with a resilientrubber-like polymer.

19. An explosively actuated punching tool according to claim 18 whereinsaid punching tool is a cable swaging tool.

No references cited.

